Memory switching circuit



P. M. CASTLE MEMORY SWITCHING CIRCUIT Filed Feb. 17, 1964 Feb.28, 1967fl5v. 46

MIXER I06 g g N 42 I0 I v 4 u s 66 l N QO I 80' III L so 72 E 96 W1 104S 62 I 74 IT: BY FIG? 3 INVENTOR. PATRICK M. CASTLE BUCKHORNBLORE,KLARQU|ST a SPARKMAN ATTORNEYS United States Patent 3,307,050MEMORY SWITCHING CIRCUIT Patrick M. Castle, Hillsboro, 0reg., assignorto Rodgers Organ Co., Hillsboro, 0reg., a corporation of Oregon FiledFeb. 17, 1964, Ser. No. 345,159 8 Claims. (Cl. 307-112) The subjectmatter of the present invention relates generally to electrical circuitsfor controlling the operation of mechanical switches, and in particularto switching circuits having memory devices for automatically moving thecontacts of switches to preset positions after energizing such memorydevices to determine such preset positions.

Briefly, one embodiment of the present switching circuit includes amemory device in the form of a pair of reed switches having magneticcontacts which are opened and closed by energizing one of a pair ofoperating coils associated with such reed switches, and are held in aclosed position by means of a pair of permanent magnets supportedadjacent the reed switches. The movable contact of the mechanical switchwhose position is to be controlled, is first connected in series withone of the operating coils in one of its two switch positions and then acircuit through this coil is completed so that current flows throughthis coil to produce a magnetic field which closes one and opens theother of the reed switches. This sets the predetermined position of themechanical switch because the closed reed switch is held in thatposition by its permanent magnet. Then, regardless of the position towhich the mechanical switch is subsequently moved manually, it can laterbe caused to return automatically to the preset position determined bythe magnetic memory circuit merely by completing a circuit which isconnected to both of the reed switches to cause current to flow throughthe closed reed switch and one of two actuating coils connected to suchreed switches. The actuating coils are associated with the mechanicalswitch so that the energized coil automatically moves the movablecontact of such switch into its preset position.

The switching circuit of the present invention is especially useful whenemployed for controlling the operation of mechanical switches in theelectrical circuits of musical instruments, such as electronic or pipeorgans. This switching circuit may be employed as a stop combinationcapture circuit in such organ which functions as a memory circuit for aparticular combination of stop switches on the organ. Before playing anorgan the musician presets different combinations of stops on such organand captures or stores these combinations by simultaneously closing acombination switch and capture switch on the organ momentarily.Subsequently, while playing the organ it is then only necessary to closethe combination switch in order to reproduce the preset combination ofstops.

The present memory switching circuit has several advantages overprevious stop combination capture systems, including a simpler and lessexpensive structure. Furthermore, the present circuit has fewer movingparts and is more reliable than conventional capture systems consistingentirely of mechanical switches. Furthermore, the present switchingcircuit is of a small physical size, dissipates little power, is lightin weight and generates little heat.

It is therefore one object of the present invention to provide a memoryswitching circuit for controlling the operation of a mechanical switchso that the movable contact of such switch is automatically placed in apredetermined position.

Another object of the invention is to provide an improved switchingcircuit for an electronic musical instrument which controls thepositions of a plurality of switches ice in an efficient and reliablemanner in order to provide a plurality of different predeterminedcombinations of musical tones.

A further object of the present invention is to provide an improved stopcombination capture circuit for automatically controlling the positionof stop switches in an electronic or pipe organ, which is simple andinexpensive.

An additional object of the present invention is to provide an improvedstop combination capture circuit which is compact and light weight andwhich generates little heat and dissipates a small amount of power.

Other objects and advantages of the present invention will be apparentfrom the following detailed description of certain preferred embodimentsthereof and from the attached drawings of which:

FIG. 1 is a schematic block diagram of an electrical circuit forproducing a plurality of different musical tones by closing differentcombinations of stop switches in an electronic organ;

FIG. 2 is a schematic circuit diagram of one embodiment of the stopcombination capture circuit of the present invention which may beemployed to control the position of the stop switches shown in FIG. 1;

FIG. 3 is a schematic diagram of a portion of another embodiment of astop combination capture circuit similar to that of FIG. 2; and

FIG. 4 is a schematic diagram of another embodiment of a magnetic switchwhich may be used in the circuits of FIGS. 2 and 3.

As shown in FIG. 1, an electronic organ may be provided with a separatetone generation circuit for each key 10 of the organ manuals. Themovable contact of key 10 is connected to a negative D.C. supply voltageof about -15 volts and the fixed contact of such key is connectedthrough a plurality of stop switches 12, 14 and 16 to separateindividual signal generators 18, 20 and 22, respectively, which produceoutput signals of different frequency. The output of each of thesesignal generators may be connected through a plurality of different stopswitches 24, 26 and 28 and filters 30, 32 and 34, respectively, ofdifferent signal transmission characteristics associated therewith to amixer amplifier 36. The output of the mixer amplifier 36 is connected toa loud speaker 38. Thus, when the key 10 is closed along with one ormore stop switches 12, 14 and 16, at least one of the signalgeneratorsis energized by the DO supply voltage connected to the movablecontact of such key. The output signal produced by such signal generatoris then transmitted through one or more of the filters 30, 32 and 34 byclosing at least one of the stop switches 24, 26 and 28 associated witheach signal generator. The filtered signals have different waveforms andare combined by the mixer amplifier 36 to produce a combination ofsignals which are transmitted to the loud speaker 38 to convert suchsignals into sound. Therefore, it can be seen that the output sound ofthe loud speaker may be varied merely by closing different ones of thestop switches to change the combination of signals transmitted to themixer amplifier 36. The combinations of stop switches may be stored bymeans of the stop combination capture circuits of FIG. 2 or 3.

As shown in FIG. 2, one embodiment of the stop combination capturecircuit of the present invention includes a two position stop tab switch40 which may be ganged to the stop switch 12 of FIG. 1 so that movementof such stop talb switch also causes the stop switch to move to acorresponding open or closed position. The movable contact of the stoptab switch 40 is connected to ground while the upper and lower fixedcontacts of such tab switch are connected through operating coils 42 and44, respectively, to the emitter of a first switching or gatingtransistor 46 of the PNP type whose collector is connected to a sourceof negative D.C. supply voltage of about 15 volts. The cathode of anisolating diode 48 is connected to the emitter of gating transistor 46and the anode of such diode is connected to the common end terminals ofcoils 42 and 44 so that current can flow only in one direction throughsuch coils. The gating transistor 46 is normally biased nonconductingand the base of the transistor is connected through a magneticallyoperated control switch 50 and a combination switch 52 to a source ofnegative DC. bias voltage of about 15 volts for rendering suchtransistor conducting.

The movable contact of control switch 50 is normally positioned inengagement with its lower fixed contact and is moved upward intoengagement with its upper fixed contact by closing a capture switch 54.The capture switch 54 is connected between a source of negative D.C.supply voltage of about l volts and a solenoid coil 55 which is woundabout a solenoid core 56 and grounded at one end so that energization ofsuch coil causes the solenoid core to move upward. The solenoid core isattached to the movable contact of the control switch 50 and rotatessuch contact counterclockwise into engagement with the upper fixedcontact of such switch. Thus, when both the capture switch 54 and thecombination switch 52 are closed simultaneously the negative D.C. supplyvoltage connected to such combination switch, is applied across a biasresistor 58 to the base of transistor 46 and renders such transistorconducting. This causes current to flow through the gating transistorand one of the coils 42 and 44 to ground depending upon the position ofthe stop tab switch 40.

The operating coils 42 and 44 are wound in opposite direction about apair of magnetic reed switches 60 and 62, having contact members of softiron or other high permeability magnetic material. Each magnet of a pairof permanent magnets 64 and 66 is positioned adjacent a dilTerent one ofthe magnetic switches 60 and 62, re-

spectively, at a position so that they exert a magnetic force on theassociated magnetic switches which is insufiicient by itself to closetheir switch contacts. The magnetic flux from the permanent magnetspasses through the switches in opposite directions so that current flowthrough one of the coils produces a magnetic field of a polarity whichis added to the field of one of the magnets and subtracted from thefield of the other magnet. The field strengths are such that they causeone of the magnetic switches to open and the other magnetic switch toclose. Thus, current flowing through coil 42 produces a field of onepolarity which causes magnetic switch 62 to close and magnetic switch 60to open, while current flow through coil 44 produces a field of theopposite polarity which causes switch 60 to close and switch 62 to open.The permanent magnets alone hold such contacts closed after they aremoved to that position by the magnetic field of the coils 42 and 44.This means that the magnetic switches function as memory switches sincethey stay in an open or closed position after such coils arede-energiz'ed. v

One of the contacts of each of the magnetic switches 60 and 62 isconnected through an isolating diode 68 to the emitter of a PNP typeswitching or gating transistor 70 whose collector is connected to asource of negative D.C. supply voltage of about -15 volts. The othercontact of each of the magnetic switches 60 and 62 is connected throughone of a pair of actuating coils 72 and 74 to ground. The base oftransistor 70 is connected to the lower fixed contact of the controlswitch and thus is normally connected by such control switch to thefixed contact of the combination switch 50. Therefore when captureswitch 54 is open, momentary closure of such combination switch appliesa negative D.C. supply voltage across an input resistor 76 to the baseof such transistor. This renders the gating transistor 70 conducting andcauses current to flow to ground through one of the actuating coils 72and 74 depending upon which of the magnetic switches 60 and 62 isclosed. The coils 72 and 74 are each associated with the stop tab switch40 so that when energized they move the movable contact of such switchto one of its two switch positions. The actuating coils 72 and 74 are soarranged that they cause the movable contact of the stop tab switch 40to be placed in the original position necessary to close the magneticswitch connected to such coil. Thus, current flow through actuating coil72 rotates the movable contact of the stop tab switch 40 into the lowerposition shown to ground one end of the operating coil 44. In a similarmanner when actuating coil 74 is energized it causes the movable contactof the stop tab switch 40 to move to the upper position to ground oneend of the operating coil 42. As a result, the magnetic memory deviceincluding actuating coils 42 and 44, magnetic switches 60 and 62 andpermanent magnets 64 and 66 causes the movable contact of the stop tabswitch 40 to be moved automatically into the predetermined position,originally set by first manually moving the stop tab switch in thatposition and then closing both the combination switch 52 and the captureswitch 54, merely by subsequently closing only the combination switch.Since the movable contact of the stop tab switch 40 is ganged to themovable contact of the stop switch 12, such stop switch is also moved toits predetermined open or closed position.

Each combination switch of the present circuit may have a plurality oforgan stop switches associated therewith. Thus, combination switch 52may be connected through the control switch 50 and gating transistor 46to a second stop tab switch 78. The fixed contacts of the stop tabswitch 78 are connected through a second pair of operating coils 80 and82 in a similar manner to coils 42 and 44. Each of these coils 80 and 82is associated with a second pair of magnetic reed switches 84 and 86 foropening one and closing the other of such switches when one of theoperating coils is energized. A second pair of permanent magnets 88 and90 are supported adjacent reed switches 84 and 86, respectively, to holdsuch switches closed. Each of the reed switches is connected between theemitter of gating transistor 70 and ground through a ditferent one of asecond pair of actuating coils 92 and 94 respectively. The groundedmovable contact of the stop tab switch 78 may be ganged to the movablecontact of the stop switch 26 of FIG. 1. This second magnetic memorycircuit functions in a similar manner to the magnetic memory c-ircuitdescribed above so that it will not be described in detail. Thus, if itis desired to cause the signal generator 18 of FIG. 1 to produce anoutput signal and to transmit such output signal through filter 32, itis necessary to close stop switches 12 and 26. This combination of stopswitches can be stored by manually placing the movable contact of stoptag switch 40 in its upper position and by manually placing the movablecontact of stop tab switch 78 to its upper position before closingcombination switch 50 and capture switch 54 simultaneously for a shortperiod of time. This causes coils 42 and 80 to be energized and closesthe contacts of magnetic switches 62 and 86 while opening the contactsof magnetic switches 60 and 84. Permanent magnets 66 and 90 hold thecontacts of magnetic switches 62 and 86, respectively, closed. Thus,when the combination switch 52 is again momentarily closed at somesubsequent time, actuating coils 74 and 90 are energized by currentflowing through the closed magnetic switches 62 and 86 to automaticallymove the movable contacts of the stop tab switches 40 and 78 to theirupper positions regardless of the position into which such movablecontacts have been manually placed during the interim.

It should be noted that more stop tab switches whose movable contactsare ganged to other stop switches of FIG. 1 may be provided in FIG. 2along with associated memory circuits connected to gating transistors 46and 7a so that several different combinations of stop switches may becaptured or stored by such circuit. In this regard a second combinationswitch 52' may be connected through a second control switch 50' to oneof a pair of gating transistors 46 and 70'. These gating transistors arealso connected through separate magnetic memory devices to stop tabswitch 40 and the stop tab switch 78 and to the common actuating coilsof such stop tab switches in a similar manner to the gating transistors46 and 70 described above. The same reference numerals, except forprimes, have been used on the elements of such additional magneticmemory devices which correspond to similar elements of the abovementioned memory devices.

Therefore, these additional magnetic memory devices willv not bedescribed in detail for this reason. The second combination switch 52 isclosed momentarily at the same time as the capture switch 54 in order tostore a different combination of stop switch positions than that storedby closing the combination switch 52. Of course, in order to do thiswith the circuit of FIG. 2 it would be necessary to provide a third stoptab switch ganged to either stop switch 24 or stop switch 28 of FIG. 1,together with an associated magnetic memory device and actuating coilsfor such stop tab switch.

A second embodiment of the stop combination capture circuit of thepresent invention may be provided by changing the circuit of FIG. 2 asshown in FIG. 3. Since this embodiment is similar to that shown in FIG.2, only a portion of the circuit is shown and the same referencenumerals have been employed to designate similar elements. The primarydifference between these two circuits is that the operating coils 42 and44 in the circuit of FIG. 3 are connected through activating coils 72and 74, respectively, to the fixed contacts of a stop tab switch 96whose movable contact is grounded and ganged to stop switch 12. Theother end of each of the coils 42 and 44 is connected through a separateisolating diode 98 and 100, respectively, to the emitter of gatingtransistor 46. When such gating transistor is rendered conducting byclosing both the combination switch and the capture switch, currentflows through one of the operating coils and one of the actuating coilsto ground. This current is suflicient to cause one of the magneticswitches 60 and 62 to close while opening the other of such magneticswitches, but is insufficent to cause the actuating coil to change theposition of the movable contact of the stop tab switch 96. One of themovable contacts of each of the magnetic switches 60 and 62 is connectedthrough a different one of a pair of isolating diodes 102 and 104,respectively, to the emitter of gating transistor 70. When gatingtransistor 70 is rendered conducting by closing the combination switch,suflicient current flows through the closed magnetic switch, held inthat condition by one of the permanent magnets 64 and 66, to energizethe actuating coil.

Thus, if in FIG. 3 the movable contact of the stop tab switch 96 isoriginally placed in the upper position, o crating coil 42 is energizedby closing both the combination switch and the capture switch to rendertarnsistor 46 conducting. This causes magnetic switch 60 to open, andmagnetic switch 62 to close and to be held in that position by permanentmagnet 66. Therefore, when the combination switch alone is closed at alater time to render gating transistor 70 conducting, current will flowthrough the closed magnetic switch 62 and the actuating coil 74, if themovable contact of the stop tab switch 96 is then in the lower positionshown. However, cur-rent flow through coil 74 causes such coil to rotatethe movable contact of the stop tab switch back to its preset upperposition. It should be noted that this is possible because the stop tabswitch 96 is of the Klann type so that it will continue to move to theupper position even after the actuating coil 74 is de-energized by thestop ta-b switch breaking the connection of the coil to ground.

It should be noted that the additional isolating diodes 6. 98, 100, 102and 104 are employed in the circuit of FIG. 3 to prevent the samecurrent from flowing through the operating coils 42 and 44 and themagnetic switches and 62. The current flowing through gating transistor46 cannot flow through either of the magnetic switches 60 or 62 due tothe polarity of isolating diodes 102 and 104, while current flowingthrough gating transistor cannot flow through the coils 42 and 44 due tothe polarity of isolating diodes 98 and 100. Also, a pair of shuntingdiodes 106 and 108 may be connected in parallel with the operating coils42 and 44, respectively. These shunting diodes are for the purpose ofpreventing transient switching currents from causing undesired operationof the reed switches 60 and 62 resulting in loss of the memory switchposition. Each of the operating coils in the circuit of FIG. 2 may beprovided with a shunt diode for this reason. However, such diodes havebeen found to be unnecessary in some cases and can be eliminated.

As shown in FIG. 4, a two position reed switch 110 can be substitutedfor each pair of switches 60 and 62, 84 and 36 in the circuits of FIGS.2 and 3, and the pair of permanent magnets 64 and 66, 88 and maylikewise be replaced by a single permanent magnet 112. The magnet 112 ispositioned with its opposite poles adjacent different ones of the fixedcontacts 114 and 116 of such reed switch but insulated therefrom. Themovable contact 118 of the switch and the fixed contacts 114 and 116 aremade of magnetic material so that such movable contact is moved intoengagement with one of the fixed contacts by energizing one of theoperating coils 42 and 44 and is held in that position by magnet 112.The operating coils are wound in opposite directions about the switch110 to produce magnetic fields of opposite polarity when they areenergized so that coil 42 closes contacts 116 and 118 and coil 44 closescontacts 114 and 118. Thus the reed switch 110 operates in a similarmanner to each pair of reed switches of FIGS. 2 and 3.

It will be obvious to those having ordinary skill in the art thatvarious changes may be made in the details of the above describedembodiments of the present invention without departing from the spiritof the invention. Thus it is to be noted that the gating transistors 46,70, 46 and 70 are employed for the purpose of reducing the currentflowing through the contacts of the control switches 50 and 50 and thecombination switches 52 and 52'. Thus these transistors can be omittedif switches capable of carrying greater currents are employed.Therefore, the scope of the present invention should only be determinedby the following claims.

I claim:

1. A memory switching circuit, comprising:

a source of current;

magnetic memory switch means having a pair of current paths;

a pair of operating coils supported adjacent to said memory switch meansfor closing one and opening the other of said current paths when one ofsaid operating coils is energized;

a control switch means including a first portion connected between saidcurrent source and said memory switch means, and a second portionconnected between said current source and said pair of operating coils,for transmitting current to either said memory switch means or to saidoperating coils depending upon the conductive condition of said portionsof said control switch means;

an operating switch means for enabling a different one of said operatingcoils to be energized by said second portion of said control switchmeans in each of two switch positions of said operating switch means;and

a pair of actuating coils each connected to a different one of saidcurrent paths of said memory switch means for placing said operatingswitch means in the position set by said second portion of said controlswitch means, when said first portion of said control switch means isrendered conducting.

A memory switching circuit for an electronic musical instrument,comprising:

a control means including a capture switch, a combination switch and acontrol switch connected so that said control switch enables current toflow through said operating coils when said capture switch is closed,and said control switch enables current to flow through said magneticswitch means when said combination switch is closed;

an operating switch means for enabling a difierent one of operatingcoils to be energized by said control switch in each of two switchpositions of said operating switch means; and

pair of actuating coils each connected to a different one of the currentpaths of said magnetic switch means for automatically changing theposition of said operating switch means to that set by closing saidcapture switch, in response to current flow through the closed path ofsaid magnetic switch means when said combination switch is closed.

A memory switching circuit for an electronic musical instrument,comprising:

a pair of first and second gating devices;

pair of first and second control switch means for rendering said gatingdevices conducting, said first gating device becoming conductive whenboth of said control switch means are actuated and said second gatingdevice becoming conductive if only said first control switch means isactuated;

pair of first and second memory switch means connected to the secondgate means, each of said memory switch means including a magnet;

pair of first and second operating coil means connected to the firstgate means for actuating said first and second memory switch means inresponse to current flow through said first gate means;

an operating switch means for energizing a different one of saidoperating coil means in each of two switch positions to render one ofsaid memory switch means conducting and the other memory switch meansnonconducting and to reverse the conductive conditions of said memoryswitch means;

means for applying a voltage between said operating means for applying avoltage between the other termi nal of each of said actuating coil meansand said second gating device. A memory switching circuit for anelectronic musical instrument, comprising:

a pair of first and second gating devices; a pair of first and secondcontrol means for rendering said gating devices conducting, said firstgating device becoming conductive when both of said control means areactuated and said second gating device becoming conductive if only saidfirst control means is actuated;

a pair of first and second magnetic memory switch means connected to thesecond gate means;

a pair of first and second operating coil means connected to the firstgate means for actuating said first and second memory switch means inresponse to current flow through said first gate means;

an operating switch means for energizing a different one of saidoperating coil means in each of two switch positions to render one ofsaid memory switch means conducting and the other memory switch meansnonconducting and to reverse the conductive conditions of said memoryswitch means; and

means for applying a voltage between said operating switch means andsaid first and second gating devices; and

a pair of first and second actuating coil means each connected betweensaid operating switch means and a different one of said pair of saidoperating coil means and said pair of memory switch means for changingthe position of said operating switch means to that set by actuatingboth of said control means, in response to current flow through thesecond gating device and the conducting one of said pair of memoryswitch means when said second gating device is rendered conducting bysaid first control means.

5. A capture circuit for an electronic organ, comprising:

a pair of first and second gating devices;

a capture switch means having a first fixed contact connected to theinput of said first gating device, a second fixed contact connected tothe input of said second gating device, and a movable contact normallyconnected to said second fixed contact;

an input terminal;

a stop combination switch connected between said input terminal and themovable contact of said capture switch means;

a pair of operating coils each having one end connected to the output ofsaid first gating device;

a stop tab switch having a movable contact connected to ground anda'pair of fixed contacts each connected to the other end of a differentone of the operating coils, to energize one of said coils by closingsaid combination switch and actuating said capture switch means to moveits movable contact to said first fixed contact and cause current toflow through said first gating device when said one coil is grounded;

a two position magnetic switch having a movable contact connected to theoutput of said second gating device and a pair of fixed contacts, saidmagnetic switch being positioned adjacent said operating coils so thatenergization of one of the coils causes the movable contact and one ofthe fixed contacts to close and the other fixed contact to open andenergization of the other coil reverses the conductive condition of suchfixed contacts;

a permanent magnet positioned adjacent said fixed contacts and applyinga magnetic field of sufficient strength to hold the contacts of saidmagnetic switch closed but not sufficient to close such contacts; and

a pair of actuating coils each having one end connected to a ditferentone of said fixed contacts of said mag-l netic switch and having itsother end grounded, said actuating coils being positioned adjacent themovable contact of said stop switch so that when one of the actuatingcoils is energized by closing said combination switch to cause currentto flow through said second gating deviceand the closed contacts of saidmagnetic switch, said one actuating coil places such movable contactinto the position required to energize the proper operating coil toclose such closed contacts of said magnetic switch.

ing:

6. A capturecircuit for an electronic organ, comprisa pair of first andsecond transistors; a capture switch means having a first fixed contactcona voltage source; a stop combination switch connected between saidvoltage source and the movable contact of said capture switch means;

a pair of operating coils each having one end connected ing:

to the output of said first transistor;

stop tab switch having a movable contact connected to ground and a pairof fixed contacts each connected to the other end of a different one ofthe operating coils, to energize one of said coils by closing saidcombination switch and actuating said capture switch means to move itsmovable contact to said first fixed contact and cause current to flowthrough said first transistor when said one coil is grounded;

pair of normally open magnetic reed switches each having one contactconnected to the output of said second transistor, said magneticswitches each being positioned adjacent said operating coils so thatenergization of one of the coils causes one of the magnetic switches toclose and the other to open and energization of the other coil reversesthe conductive condition of such magnetic switches;

pair of permanent magnets each positioned adjacent a different one ofsaid magnetic switches and applying a magnetic field of sufficientstrength to hold the contacts of its associated magnetic switch closedbut not sufficient to close such contacts; and

first pair of actuating coils connected between said operating coils andthe fixed contacts of the stop tab switch and each of said actuatingcoils having one end connected to the other contact of a different oneof said magnetic switches, said actuating coils being positionedadjacent the movable contact of the first stop switch so that when oneof such coils is energized by closing said combination switch to causecurrent to flow through said second transistor and the closed one ofsaid magnetic switches, said one actuating coil places such movablecontact into the position required to energize the proper operating coilto close such closed magnetic switch.

A capture circuit for an electronic organ, comprisa voltage source; astop combination switch connected between said voltage source and themovable contact of said control switch;

first pair of operating coils each having one end connected to theoutput of said first transistor; first stop tab switch having a movablecontact con" nected to ground and a pair of fixed contacts eachconnected to the other end of a different one of the first pair ofcoils, to energize one of said first coils by closing said combinationswitch and said capture 10 switch to cause current to flow through saidfirst transistor when said one coil is grounded;

a first pair of normally open magnetic switches each having one contactconnected to the output of said second transistor, said first magneticswitches each being positioned adjacent said first operating coils sothat energization of one of the coils causes one of the magneticswitches to close and the other to open and energization of the othercoil reverses the conductive condition of such magnetic switches;

a first pair of permanent magnets each positioned adjacent a differentone of said first magnetic switches and applying a magnetic field ofsufficient strength to hold the contacts of its associated magneticswitch closed but not sufficient to close such contacts;

a first pair of actuating coils each having one end connected to theother contact of a different one of said first magnetic switches andhaving its other end grounded, said first actuating coils beingpositioned adjacent the movable contact of the first stop switch so thatwhen one of such coils is energized by closing said combination switchto cause current to flow through said second transistor and the closedone of said first magnetic switches it moves such movable contact to theposition required to energize the proper inductance coil to close suchclosed magnetic switch;

a second pair of operating coils;

a second stop tab switch;

a second pair of magnetic switches;

a second pair of permanent magnets; and

a second pair of actuating coils, said second actuating coils, secondoperating coils, second magnets, second magnetic switches and secondstop switch being connected to said transistors, said control switch andsaid stop combination switch in a similar manner to the correspondingfirst elements.

8. A stop combination capture circuit for an electronic organ,comprising:

a plurality of pairs of gating transistors;

a plurality of magnetic memory devices connected to each pair oftransistors, each of said memory devices including a pair of operatingcoils and a pair of reed switches connected to different ones of saidpair of transistors, a pair of shunting diodes across said operatingcoils, and a pair of permanent magnets each supported adjacent adifferent one of said reed switches;

a plurality of stop tab switches each connected to a plurality ofdifferent pairs of said operating coils so that a different one of thecoils of each pair of operating coils is energized in each of twopositions of the stop tab switches;

a plurality of pairs of actuating coils supported for movement of saidstop tab switches with a different pair of actuating coils associatedwith each stop tab switch;

a plurality of stop combination switches each normally connected to onetransistor of a different pair of gating transistors; and

a common capture switch means for connecting all of said combinationswitches to the other transistor of the pair of transistors associatedtherewith.

References Cited by the Examiner UNITED STATES PATENTS 3,042,900 7/1962Werts 340-468 ORIS L. RADER, Primary Examiner.

7 T. B. JOIKE, Assistant Examiner.

1. A MEMORY SWITCHING CIRCUIT, COMPRISING: A SOURCE OF CURRENT; MAGNETICMEMORY SWITCH MEANS HAVING A PAIR OF CURRENT PATHS; A PAIR OF OPERATINGCOILS SUPPORTED ADJACENT TO SAID MEMORY SWITCH MEANS FOR CLOSING ONE ANDOPENING THE OTHER OF SAID CURRENT PATHS WHEN ONE OF SAID OPERATING COILSIS ENERGIZED; A CONTROL SWITCH MEANS INCLUDING A FIRST PORTION CONNECTEDBETWEEN SAID CURRENT SOURCE AND SAID MEMORY SWITCH MEANS, AND A SECONDPORTION CONNECTED BETWEEN SAID CURRENT SOURCE AND SAID PAIR OF OPERATINGCOILS, FOR TRANSMITTING CURRENT TO EITHER SAID MEMORY SWITCH MEANS OR TOSAID OPERATING COILS DEPENDING UPON THE CONDUCTIVE CONDITION OF SAIDPORTIONS OF SAID CONTROL SWITCH MEANS; AN OPERATING SWITCH MEANS FORENABLING A DIFFERENT ONE OF SAID OPERATING COILS TO BE ENERGIZED BY SAIDSECOND PORTION OF SAID CONTROL SWITCH MEANS IN EACH OF TWO SWITCHPOSITIONS OF SAID OPERATING SWITCH MEANS; AND A PAIR OF ACTUATING COILSEACH CONNECTED TO A DIFFERENT ONE OF SAID CURRENT PATHS OF SID MEMORYSWITCH MEANS FOR PLACING SAID OPERATING SWITCH MEANS IN THE POSITION SETBY SAID SECOND PORTION OF SAID CONTROL SWITCH MEANS, WHEN SAID FIRSTPORTION OF SAID CONTROL SWITCH MEANS IS RENDERED CONDUCTING.